Oxidative stress and gene regulation

Effects of glyphosate on the ovarian function of pregnant mice, the secretion of hormones and the sex ratio of their fetuses

Glyphosate is the active ingredient of the commercial formulation Roundup®, which is used worldwide. This study aimed to investigate the toxic effects of pure glyphosate or Roundup® on pregnant mice and their fetuses during pregnancy. From gestation days (GDs) 1-19, ICR mice were orally administered distilled water, 0.5% glyphosate solution or 0.5%-glyphosate Roundup® solution. The ovaries and serum were collected at GD19. The results showed decreases in body weight gain and, ovary and liver weight in glyphosate-treated mice. Additionally, histopathological alterations in the ovary including increased atretic follicles, interstitial fibrosis and decreased mature follicles were observed in the groups treated with glyphosate. The serum concentrations of both progesterone and estrogen were markedly altered after glyphosate exposure, and there were also changes in the expression of GnRH, LHR, FSHR, 3β-HSD and Cyp19a1 genes at the hypothalamic-pituitary-ovarian axis. Furthermore, oxidative stress was observed in the treated mice, increasing the activity of T-AOC, CAT and GSH-Px, as well as the MDA content in both the serum and ovary. With regard to litters, the sex ratio was significantly altered by pure glyphosate. These results show that glyphosate is able to cause several effects on pregnant mice, such as ovarian failure, interference with hormone secretion by affecting the steroidogenesis-related gene expression, and oxidative stress. The sex ratio of litters was also influenced by prenatal exposure to pure glyphosate.

Combined toxicity of organophosphate flame retardants and cadmium to Corbicula fluminea in aquatic sediments

Organophosphate flame retardants (OPFRs), as alternatives to polybrominated biphenyl ethers (PBDEs), are frequently detected in various environmental matrices. Owing to urbanization and industrial pollution, co-contamination of OPFRs and heavy metals is ubiquitous in the environment. The toxicity of OPFRs in aqueous phase is a significant concern, but uncertainty still exists regarding the co-toxicity to benthic organisms of OPFRs and metals in sediments. Hence, we explored the physiological response of Corbicula fluminea to OPFRs and Cd in sediments. The results indicated that the antioxidant system in the clams was stimulated in the presence of OPFRs and Cd, and the oxidative stress increased with increasing concentrations of OPFRs. In contrast, the cytochrome P450 (CYP450) content and acetylcholinesterase (AChE) activity were reduced by exposure to both OPFRs and Cd. The cytochrome P450 4 family (CYP4) mRNA expression and OPFR toxicity were lower than those in previously reported experiments conducted in the water phase. Moreover, the expression levels of metallothionein (MT) and AChE mRNA decreased when OPFRs and Cd were present together. The highest integrated biomarker response (IBR) index (IBR = 15.41) was observed in the presence of 45 mg kg^-1 Cd + 200 mg kg^-1 OPFRs, rather than the 45 mg kg^-1 Cd + 400 mg kg^-1 OPFRs treatment (IBR = 9.48). In addition, CYP450 and AChE in the digestive glands of C. fluminea exhibited significant correlations with the concentration of the OPFR/Cd mixture (p < 0.01) and could be effective biomarkers for OPFR and Cd co-contamination. The results potentially contribute to more realistic predictions and evaluations of the environmental risks posed by OPFRs in aquatic sediments contaminated with heavy metals, particularly with respect to the risk to benthic organisms.

A New Mixed-Valence Mn(II)Mn(III) Compound With Catalase and Superoxide Dismutase Activities

The synthesis, X-ray molecular structure, physico-chemical characterization and dual antioxidant activity (catalase and superoxide dismutase) of a new polymeric mixed valence Mn(III)Mn(II) complex, containing the ligand H₂BPClNOL (N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)[(3-chloro)(2-hydroxy)] propylamine) is described. The monomeric unit is composed of a dinuclear Mn(II)Mn(III) moiety, [Mn(III)(μ-HBPClNOL)(μ-BPClNOL)Mn(II)(Cl)](ClO₄)·2H₂O, 1, in which the Mn ions are connected by two different bridging groups provided by two molecules of the ligand H₂BPClNOL, a phenoxide and an alkoxide group. In the solid state, this mixed valence dinuclear unit is connected to its neighbors through chloro bridges. Magnetic measurements indicated the presence of ferromagnetic [J = +0.076(13) cm⁻¹] and antiferromagnetic [J = −5.224(13) cm⁻¹] interactions. The compound promotes O2•- dismutation in aqueous solution (IC₅₀ = 0.370 μmol dm⁻³, k_cat = 3.6x10⁶ M⁻¹ s⁻¹). EPR studies revealed that a high-valent Mn(III)-O-Mn(IV) species is involved in the superoxide dismutation catalytic cycle. Complex 1 shows catalase activity only in the presence of a base, e.g., piperazine or triethylamine. Kinetic studies were carried out in the presence of piperazine and employing two different methods, resulting in k_cat values of 0.58 ± 0.03 s⁻¹ (detection of O₂ production employing a Clark electrode) and 2.59 ± 0.12 s⁻¹ (H₂O₂ consuption recorded via UV-Vis). EPR and ESI-(+)-MS studies indicate that piperazine induces the oxidation of 1, resulting in the formation of the catalytically active Mn(III)-O-Mn(IV) species.

The effects of salicylic acid and glucose on biochemical traits and taxane production in a Taxus baccata callus culture

The combined use of elicitors can be an effective way to increase the production of secondary metabolites (SMs) in plant cell, tissue and organ cultures. This study investigated the effects of a salicylic acid (SA) pretreatment and different glucose levels on the growth, biochemical traits and taxane production in a Taxus baccata callus culture. For this purpose, after a pretreatment with SA (5 μM), three-month-old calli were cultured on B5 medium fortified with different concentrations of glucose (0, 0.5, 1, 2 and 3%), and they were compared with calli cultured on a B5 medium supplemented only with glucose. When the calli were harvested at 21 days, their fresh weight (g), dry weight (g) and cell viability (%) had decreased significantly (p < 0.05) with the higher glucose concentrations. The glucose treatment increased the hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) content, and caused oxidative stress in treated tissues. The lower H₂O₂ content and oxidative stress was associated with an increased antioxidant enzyme activity in the SA-pretreated samples, which resulted in less membrane damage and improved growth and cell viability under the glucose treatment compared to the control. By reducing the activity of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO), the SA pretreatment reduced the production and oxidation of phenolic compounds under the glucose treatment; this decrease was associated with less browning of tissues and higher viability. Increases in taxol (5.1-fold) and total taxanes (3.5-fold) in the SA-pretreated calli cultured on the medium containing 2% glucose, compared to the control, indicated that the two treatments had a significant effect on taxane production in the T. baccata callus culture.

Insights into the respiratory chain and oxidative stress

Reactive oxygen species (ROS) are highly reactive reduced oxygen molecules that result from aerobic metabolism. The common forms are the superoxide anion (O2∙-) and hydrogen peroxide (H2O2) and their derived forms, hydroxyl radical (HO∙) and hydroperoxyl radical (HOO∙). Their production sites in mitochondria are reviewed. Even though being highly toxic products, ROS seem important in transducing information from dysfunctional mitochondria. Evidences of signal transduction mediated by ROS in mitochondrial deficiency contexts are then presented in different organisms such as yeast, mammals or photosynthetic organisms.

Varicocele repair in patients prepared for intracytoplasmic sperm injection: To do or not to do?

PURPOSE

This study sought to evaluate the impact of varicocele repair on intracytoplasmic sperm injection outcomes.

PATIENTS AND METHODS

A prospective comparative study was conducted at the Assisted Reproduction Unit, International Islamic Center for Population Studies and Researches, Al-Azhar University. This study included 100 non-azoospermic infertile men with a history of varicocele who were scheduled for intracytoplasmic sperm injection, half of them had already undergone prior subinguinal varicocelectomy at least 12 months prior to ICSI without clinically evident recurrence (treated group 1), and the other half has any grade of an unrepaired clinical varicocele (untreated group 2) at sperm injection. All cases were clinically evaluated and eligible for analysis by using inclusion and exclusion criteria. ICSI outcomes compared between the two groups, including fertilisation rate, embryo development rate and pregnancy outcome.

RESULTS

Our study did not show any significant difference between treated and untreated groups regarding the mean values of fertilisation (0.7759 ± 0.2708 vs. 0.7119 ± 0.3057, p = 0.2708), embryo development (0.7759 ± 0.2708 vs. 0.6991 ± 0.3211, p = 0.1990) or different embryo grades. There was no statistically significant difference between groups regarding pregnancy occurrence rates (p = 0.0928).

CONCLUSION

Infertile men scheduled for ICSI do not seem to benefit from varicocele repair as regard to the outcomes of ICSI.

Modulation of DNA Repair Systems in Blind Cavefish during Evolution in Constant Darkness

How the environment shapes the function and evolution of DNA repair systems is poorly understood. In a comparative study using zebrafish and the Somalian blind cavefish, Phreatichthys andruzzii, we reveal that during evolution for millions of years in continuous darkness, photoreactivation DNA repair function has been lost in P. andruzzii. We demonstrate that this loss results in part from loss-of-function mutations in pivotal DNA-repair genes. Specifically, C-terminal truncations in P. andruzzii DASH and 6-4 photolyase render these proteins predominantly cytoplasmic, with consequent loss in their functionality. In addition, we reveal a general absence of light-, UV-, and ROS-induced expression of P. andruzzii DNA-repair genes. This results from a loss of function of the D-box enhancer element, which coordinates and enhances DNA repair in response to sunlight. Our results point to P. andruzzii being the only species described, apart from placental mammals, that lacks the highly evolutionary conserved photoreactivation function. We predict that in the DNA repair systems of P. andruzzii, we may be witnessing the first stages in a process that previously occurred in the ancestors of placental mammals during the Mesozoic era.

Functional role of peroxiredoxin 6 in the eye

Peroxiredoxin 6 (Prdx6) is the only mammalian 1-Cys member of the Prdx family, a group of enzymes which share the ability to reduce peroxides. In addition to its peroxidase function, Prdx6 also demonstrates phospholipase A₂ and lysophosphatidylcholine acyl transferase (LPCAT) activities. These enzymatic activities play an important role in regenerating oxidized membrane phospholipids and maintaining an appropriate balance of intracellular reactive oxygen species. Development of clinical pathologies, including those within the eye, have been linked to dysregulation of Prdx6 function. Interplay between external stressors like exposure to UV light, transforming growth factor β (TGF-β), and hyperglycemia in conjunction with diminished Prdx6 levels and loss of redox balance is associated with cellular changes in a variety of ophthalmic pathologies including cataracts, glaucoma, and retinal degeneration. Many of these cellular abnormalities can be rescued through supplementation with exogenous Prdx6. Additionally, corneal endothelial cells have been found to express high levels of Prdx6 in the plasma membrane. These findings highlight the importance of Prdx6 as an essential regulator of oxidative stress in the eye.

Relationship between antioxidant defense in Acanthamoeba spp. infected lungs and host immunological status

The role of oxidative stress in the pathogenicity of acanthamoebiasis is an important aspect of the intricate and complex host-parasite relationship. The aim of this experimental study was to determine oxidative stress through the assessment of lipid peroxidation product (LPO) levels and antioxidant defense mechanism in Acanthamoeba spp. lung infections in immunocompetent and immunosuppressed hosts. In Acanthamoeba spp. infected immunocompetent mice we noted a significant increase in lung lipid peroxidation products (LPO) at 8 days and 16 days post infection (dpi). There was a significant upregulation in lung LPO in immunocompetent and immunosuppressed mice infected by Acanthamoeba spp. at 16 dpi. The superoxide dismutase activity decreased significantly in lungs in immunosuppressed mice at 8 dpi. The catalase activity was significantly upregulated in lungs in immunocompetent vs. immunosuppressed group and in immunocompetent vs. control mice at 16 dpi. The glutathione reductase activity was significantly lower in immunosuppressed group vs. immunosuppressed control at 24 dpi. We found significant glutathione peroxidase downregulation in immunocompetent and immunosuppressed groups vs. controls at 8 dpi, and in immunosuppressed vs. immunosuppressed control at 16 dpi. The consequence of the inflammatory response in immunocompetent and immunosuppressed hosts in the course of experimental Acanthamoeba spp. infection was the reduction of the antioxidant capacity of the lungs resulting from changes in the activity of antioxidant enzymes. Therefore, the imbalance between oxidant and antioxidant processes may play a major role in pathology associated with Acanthamoeba pneumonia.

Targeting the NLRP3 Inflammasome-Related Pathways via Tianeptine Treatment-Suppressed Microglia Polarization to the M1 Phenotype in Lipopolysaccharide-Stimulated Cultures

An increasing body of evidence postulates that microglia are the main mediators of inflammation-related disorders, including depression. Since activated microglia produce a wide range of pro- and anti-inflammatory factors, the modulation of M1/M2 microglial polarization by antidepressants may be crucial in the treatment of depression. The current paper aimed to investigate the impact of tianeptine on the microglia’s viability/death parameters, and on M1/M2 microglial activation in response to lipopolysaccharide (LPS) stimulation. Furthermore, the molecular mechanisms via which tianeptine affected the LPS-evoked changes were investigated. The results revealed that tianeptine had partially protective effects on the changes in microglia viability/death evoked by LPS. Tianeptine attenuated microglia activation by decreasing the expression of cluster of differentiation 40 (CD40), and major histocompatibility complex class II (MHC II) markers, as well as the release of pro-inflammatory factors: interleukin (IL)-1β, IL-18, IL-6, tumor necrosis factor alpha (TNF-α), and chemokine CC motif ligand 2 (CCL2), and the production of nitric oxide and reactive oxygen species. In contrast, we did not observe an impact of tianeptine on M2 microglia measured by IL-4, IL-10, TGF-β, and insulin-like growth factor 1 (IGF-1) expression. Moreover, we demonstrated an inhibitory effect of tianeptine on the LPS-induced activation of the nucleotide-binding oligomerization domain-like (NOD-like) receptor pyrin-containing 3 inflammasome (NLRP3) inflammasome subunits, NLRP3 and caspase-1, as well as the ability of tianeptine to reduce Toll-like receptor 4 (TLR4) levels, as well as the phosphorylation of extracellular signal-related kinases 1 and 2 (ERK1/2) and of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Collectively, we demonstrated that tianeptine has protective properties and inhibits M1 polarization, thus attenuating the production of inflammatory mediators. Moreover, we found that M1 microglia suppression may be related to the NLRP3 inflammasome and TLR4 signaling. These findings suggest that a better understanding of the multifaceted mechanisms of tianeptine action on microglia may increase the effectiveness of therapy, where inflammation is a central hallmark.

Transcriptomic evidence for involvement of reactive oxygen species in Rhizoctonia solani AG1 IA sclerotia maturation

Rhizoctonia solani AG1 IA is a soil-borne fungal phytopathogen that can significantly harm crops resulting in economic loss. This species overwinters in grass roots and diseased plants, and produces sclerotia that infect future crops. R. solani AG1 IA does not produce spores; therefore, understanding the molecular mechanism of sclerotia formation is important for crop disease control. To identify the genes involved in this process for the development of disease control targets, the transcriptomes of this species were determined at three important developmental stages (mycelium, sclerotial initiation, and sclerotial maturation) using an RNA-sequencing approach. A total of 5,016, 6,433, and 5,004 differentially expressed genes (DEGs) were identified in the sclerotial initiation vs. mycelial, sclerotial maturation vs. mycelial, and sclerotial maturation vs. sclerotial initiation stages, respectively. Moreover, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses showed that these DEGs were enriched in diverse categories, including oxidoreductase activity, carbohydrate metabolic process, and oxidation-reduction processes. A total of 12 DEGs were further verified using reverse transcription quantitative PCR. Among the genes examined, NADPH oxidase 1 (NOX1) and superoxide dismutase (SOD) were highly induced in the stages of sclerotial initiation and maturation. In addition, the highest reactive oxygen species (ROS) production levels were detected during sclerotial initiation, and enzyme activities of NOX1, SOD, and catalase (CAT) matched with the gene expression profiles. To further evaluate the role of ROS in sclerotial formation, R. solani AG1 IA was treated with the CAT inhibitor aminotriazole and H₂O₂, resulting in the early differentiation of sclerotia. Taken together, this study provides useful information toward understanding the molecular basis of R. solani AG1 IA sclerotial formation and maturation, and identified the important role of ROS in these processes.

Polyphenolic profiling of Ipomoea carnea Jacq. by HPLC-DAD and its implications in oxidative stress and cancer

Ipomoea carnea Jacq. is an important folklore medicinal plant, assessed for its underexplored biological potential. Antioxidant, cytotoxic, antiproliferative and polyphenolic profile of whole plant was evaluated using various techniques. Maximum extract recovery (29% w/w), phenolic [13.54 ± 0.27 μg GAE/mg dry weight (DW)] and flavonoid (2.11 ± 0.10 μg QE /mg DW) content were recorded in methanol-distilled water (1:1) flower extract. HPLC-DAD analysis quantified substantial amount of six different polyphenols ranging from 0.081 to 37.95 μg/mg extract. Maximum total antioxidant and reducing potential were documented in methanol-distilled water and acetone-distilled water flower extracts (42.62 ± 0.47 and 24.38 ± 0.39 μg AAE/mg DW) respectively. Ethanol-chloroform root extract manifested highest free radical scavenging (IC₅₀ of 61.22 μg/mL) while 94.64% of the extracts showed cytotoxicity against brine shrimps. Ethanol leaf extract exhibited remarkable activity against THP-1 cell line (IC₅₀ = 8 ± 0.05 μg/mL) and protein kinases (31 mm phenotype bald zone).

Effect of excessive doses of oxytetracycline on stress-related biomarker expression in coho salmon

Fish are exposed to a wide variety of environmental stressors, such as chemicals and acute changes in temperature. Oxytetracycline (OTC) has been used as an antibiotic for many kinds of bacterial diseases in cultured fish, but excessive doses of OTC are known to cause side effects in fish and can have negative effects on their environment. In the present study, we examined stress-related biomarker expression in response to excessive doses of dietary OTC in coho salmon (Oncorhynchus kisutch). Fish received OTC (100 mg/kg body weight/day) orally for 2 weeks. The percentage of liver to body weight (hepatosomatic index; HSI) and plasma biochemical parameter, alanine aminotransferase (ALT) activity, of the group fed a diet containing OTC were observed to be significantly higher than those of the control group. The total glutathione (tGSH) levels in the liver of OTC-fed fish were four fold higher than those in control fish and double the control levels in muscle and stomach. Plasma tGSH levels in OTC-fed fish were also higher than those in control fish. Expression levels of heat shock protein 70 in the liver, muscle, and stomach decreased by OTC administration. Accordingly, OTC-induced stress might increase the metabolic turnover of GSH due to consumption by scavenging oxidants generated by stress. These results concerning the changing patterns of stress-related biomarkers indicate that excessive doses of OTC fed to coho salmon induce oxidative stress, which might enhance oxidation in the body and result in damage to tissues, especially in the liver. The present results also suggest that tissue-specific damage caused by OTC might already exist in fish.

In-ovo exposed carbon black nanoparticles altered mRNA gene transcripts of antioxidants, proinflammatory and apoptotic pathways in the brain of chicken embryos

With ubiquitous applications of nanotechnology, there are increasing probabilities of exposure to manufactured nanoparticles (NPs), which might be posing emerging health concerns on the next generation. Recent data suggest that generation of reactive oxygen species may play an integral role in the carbon black nanoparticles (CBNPs)-induced oxidative injury; however, the exact molecular mechanism has not been clarified. Hence, the role of oxidative stress, inflammation and apoptosis pathways in the CBNPs-induced neuronal toxicity following in-ovo exposure of chicken embryo was elucidated. Specific pathogen-free fertilized Sasso eggs were inoculated with 4.8, 9.5 and 14 μg CBNPs/egg at the 3rd day of incubation alongside vehicle controls. In a concentration-dependent manner, CBNPs inoculation induced oxidative stress, which was ascertained by enhancement of lipid peroxides and diminishing total antioxidant capacity and glutathione levels, and catalase activity in brain tissues. mRNA transcript levels of antioxidant genes showed up-regulation of heme oxygenase-1 and superoxide dismutase-1, with marked down-regulation of glutathione S-transferase-α. Additionally, the pro-inflammatory genes; nuclear factor-κB1 was up-regulated, while interferon-γ was down-regulated. There is also a clear down-regulation in apoptotic markers caspase-8, caspase-3, cytochrome c and B-cell CLL/lymphoma 2 at the different concentrations, while caspase-2 is up-regulated only at higher concentration. Collectively, these results show that CBNPs exposure-mediated overproduction of the free radicals, particularly at higher concentration contributes to inflammation and subsequent cellular apoptosis at the gene expression level, thus unveiling possible molecular relationship between CBNPs and genes linked to the oxidant, inflammatory and apoptotic responses.

Mycotoxins and oxidative stress: where are we?

Mycotoxins are the most common contaminants of food and feed worldwide and are considered an important risk factor for human and animal health. Oxidative stress occurs in cells when the concentration of reactive oxygen species exceeds the cell’s antioxidant capacity. Oxidative stress causes DNA damage, enhances lipid peroxidation, protein damage and cell death. This review addresses the toxicity of the major mycotoxins, especially aflatoxin B1, deoxynivalenol, nivalenol, T-2 toxin, fumonisin B1, ochratoxin, patulin and zearalenone, in relation to oxidative stress. It summarises the data associated with oxidative stress as a plausible mechanism for mycotoxin-induced toxicity. Given the contamination caused by mycotoxins worldwide, the protective effects of a variety of natural compounds due to their antioxidant capacities have been evaluated. We review data on the ability of vitamins, flavonoids, crocin, curcumin, green tea, lycopene, phytic acid, L-carnitine, melatonin, minerals and mixtures of anti-oxidants to mitigate the toxic effect of mycotoxins associated with oxidative stress.

The impact of immunotoxicity in evaluation of the nanomaterials safety

Nanomedicinal products (NMPs), due to their unique properties, are extensively investigated for their biomedical and pharmaceutical applications. Apart from being carriers of certain drugs, nanoparticles can also interact with both the innate and adaptive immune systems, thus eliciting immune responses. Following administration, their discrete physicochemical properties make each NMP act differently in the organism. Actually, the toxic effects of NMPs, in terms of specific end points, do not necessarily depend on the specific group or structural type of the particle. Furthermore, the nanoformulation may change the pharmacokinetic/toxicokinetic profile of the drug. Unveiling the structure–activity relationship of NMPs would help to clarify their immunomodulatory effects. Therefore, in addition to the current regulatory immunotoxicity testing strategies, development and regulatory approval of nano-sized pharmaceuticals still need to be discussed in order to identify potential gaps in the safety assessment.

Meta-analysis reveals that reproductive strategies are associated with sexual differences in oxidative balance across vertebrates

Oxidative stress is a key physiological mechanism underlying life-history tradeoffs. Here, I use meta-analytic techniques to test whether sexual differences in oxidative balance are common in vertebrates and to identify which factors are associated with such differences. The dataset included 732 effect size estimates from 100 articles (82 species). Larger unsigned effect size (meaning larger sexual differences in a given marker) occurred in: reptiles and fish; those species that do not provide parental care; and oviparous species. Estimates of signed effect size (positive values meaning higher oxidative stress in males) indicated that females were less resistant to oxidative stress than males in: reptiles while males and females were similar in fish, birds, and mammals; those species that do not provide parental care; and oviparous species. There was no evidence for a significant sexual differentiation in oxidative balance in fish, birds, and mammals. Effect size was not associated with: the number of offspring; whether the experimental animals were reproducing or not; biomarker (oxidative damage, non-enzymatic, or enzymatic antioxidant), the species body mass; the strain (wild vs. domestic); or the study environment (wild vs. captivity). Oxidative stress tended to be higher in females than males across most of the tissues analyzed. Levels of residual heterogeneity were high in all models tested. The findings of this meta-analysis indicate that diversification of reproductive strategies might be associated with sexual differences in oxidative balance. This explorative meta-analysis offers a starting platform for future research to investigate the relationship between sex and oxidative balance further.

Proteomic evaluation of human umbilical cord tissue exposed to polybrominated diphenyl ethers in an e-waste recycling area

Parental exposure to polybrominated diphenyl ethers (PBDEs) is associated with adverse birth outcomes. This study aims to examine differentially-expressed protein profiles in umbilical cord tissue, derived from mothers exposed to PBDEs, and investigate candidate biomarkers to reveal the underlying molecular mechanisms. Umbilical cord samples were obtained from women residing in an electronic waste (e-waste) recycling area (Guiyu) and reference area (Haojiang) in China. The concentration of PBDEs in umbilical cord tissue was determined by gas chromatography and mass spectrometry (GC/MS). Isobaric tagging for relative and absolute quantification (iTRAQ)-based proteomic technology was conducted to analyze differentially-expressed protein profiles. The total PBDE concentration was approximately five-fold higher in umbilical cords from Guiyu than from Haojiang (median 71.92ng/g vs. 15.52ng/g lipid, P<0.01). Neonatal head circumference, body-mass index (BMI) and Apgar1 score were lower in Guiyu and negatively correlated with PBDE concentration (P<0.01). Proteomic analysis showed 697 proteins were differentially expressed in the e-waste-exposed group compared with the reference group. The differentially-expressed proteins were principally involved in antioxidant defense, apoptosis, cell structure and metabolism. Among them, catalase and glutathione S-transferase omega-1, were down-regulated, and cytochrome c was found to be up-regulated, changes which were further verified by enzyme-linked immunosorbent assays. These results suggest that an antioxidant imbalance and cell apoptosis in the umbilical cord following PBDE exposure is associated with neonatal birth outcomes.

Reprogramming human A375 amelanotic melanoma cells by catalase overexpression: Upregulation of antioxidant genes correlates with regression of melanoma malignancy and with malignant progression when downregulated

Reactive oxygen species (ROS) are implicated in tumor transformation. The antioxidant system (AOS) protects cells from ROS damage. However, it is also hijacked by cancers cells to proliferate within the tumor. Thus, identifying proteins altered by redox imbalance in cancer cells is an attractive prognostic and therapeutic tool. Gene expression microarrays in A375 melanoma cells with different ROS levels after overexpressing catalase were performed. Dissimilar phenotypes by differential compensation to hydrogen peroxide scavenging were generated. The melanotic A375-A7 (A7) upregulated TYRP1, CNTN1 and UCHL1 promoting melanogenesis. The metastatic A375-G10 (G10) downregulated MTSS1 and TIAM1, proteins absent in metastasis. Moreover, differential coexpression of AOS genes (EPHX2, GSTM3, MGST1, MSRA, TXNRD3, MGST3 and GSR) was found in A7 and G10. Their increase in A7 improved its AOS ability and therefore, oxidative stress response, resembling less aggressive tumor cells. Meanwhile, their decrease in G10 revealed a disruption in the AOS and therefore, enhanced its metastatic capacity.

These gene signatures, not only bring new insights into the physiopathology of melanoma, but also could be relevant in clinical prognostic to classify between non aggressive and metastatic melanomas.

Orthogonal Array composite design to study and optimize antioxidant combinations in the prevention of UVB-induced HSF damage

Excessive exposure to ultraviolet (UV) B radiation may lead to skin damage, photosensitivity, or even tumorigenesis via induction of oxidative stress. Naturally derived antioxidants could play significant roles in cancer therapy due to their multi-targeted actions and lack of substantial toxicity. Drug combinations target at diverse pathway of cells and make cells export meticulous biological outcomes through the multifaceted signaling network. The UVB protective effects of combinations of naturally derived antioxidants- curcumin, resveratrol, proanthocyanidins, baicalein, and beta-nicotinamide adenine dinucleotide (NADH) were investigated. An oxidative cell damage model was established to study the ultraviolet irradiation system. An orthogonal array composite design (OACD) was employed in the optimization of antioxidants combinations. Combination of resveratrol (0.1μM) and baicalein in medium concentration (0.2μM), with NADH in high concentration (0.8μM) was found to be the most efficacious combination among all the 30 runs performed using OACD. The findings suggested that UVB exposure-inflicted cell apoptosis can be significantly reduced by naturally-derived antioxidant combinations. These results provide an insight into the discovery of synergistic antioxidant combinations in skin cancer, using orthogonal array composite design (OACD). The results also have practical implications in the understanding of drug mechanisms in skin cancer, which can assist clinical practice by recommending better drug combinations.

Dietary resveratrol confers apoptotic resistance to oxidative stress in myoblasts

High levels of reactive oxygen species (ROS) contribute to muscle cell death in aging and disuse. We have previously found that resveratrol can reduce oxidative stress in response to aging and hindlimb unloading in rodents in vivo, but it was not known if resveratrol would protect muscle stem cells during repair or regeneration when oxidative stress is high. To test the protective role of resveratrol on muscle stem cells directly, we treated the C2C12 mouse myoblast cell line with moderate (100 μM) or very high (1 mM) levels of H2O2 in the presence or absence of resveratrol. The p21 promoter activity declined in myoblasts in response to high ROS, and this was accompanied a greater nuclear to cytoplasmic translocation of p21 in a dose-dependent matter in myoblasts as compared to myotubes. Apoptosis, as indicated by TdT-mediated dUTP nick-end labeling, was greater in C2C12 myoblasts as compared to myotubes (P<.05) after treatment with H2O2. Caspase-9, -8 and -3 activities were elevated significantly (P<.05) in myoblasts treated with H2O2. Myoblasts were more susceptible to ROS-induced oxidative stress than myotubes. We treated C2C12 myoblasts with 50 μM of resveratrol for periods up to 48 h to determine if myoblasts could be rescued from high-ROS-induced apoptosis by resveratrol. Resveratrol reduced the apoptotic index and significantly reduced the ROS-induced caspase-9, -8 and -3 activity in myoblasts. Furthermore, Bcl-2 and the Bax/Bcl-2 ratio were partially rescued in myoblasts by resveratrol treatment. Similarly, muscle stem cells isolated from mouse skeletal muscles showed reduced Sirt1 protein abundance with H2O2 treatment, but this could be reversed by resveratrol. Reduced apoptotic susceptibility in myoblasts as compared to myotubes to ROS is regulated, at least in part, by enhanced p21 promoter activity and nuclear p21 location in myotubes. Resveratrol confers further protection against ROS by improving Sirt1 levels and increasing antioxidant production, which reduces mitochondrial associated apoptotic signaling, and cell death in myoblasts.

Sub-cytotoxic concentrations of ionic silver promote the proliferation of human keratinocytes by inducing the production of reactive oxygen species

Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions (Ag⁺) on the proliferation of human skin keratinocytes (HaCaT) and the production of intracellular reactive oxygen species (ROS). After treating HaCaT cells with Ag⁺ and/or the active oxygen scavenger N-acetyl cysteine (NAC), cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine (BrdU) incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen (PCNA) immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag⁺ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10^-6 and 10^-5 mol/L Ag⁺ at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5-60 min after exposure to Ag⁺. The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10^-6 and 10^-5 mol/L Ag⁺, with 10^-5 mol/L Ag⁺ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag⁺ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag⁺ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.

Magnetic Fields and Reactive Oxygen Species

Reactive oxygen species (ROS) ubiquitously exist in mammalian cells to participate in various cellular signaling pathways. The intracellular ROS levels are dependent on the dynamic balance between ROS generation and elimination. In this review, we summarize reported studies about the influences of magnetic fields (MFs) on ROS levels. Although in most cases, MFs increased ROS levels in human, mouse, rat cells, and tissues, there are also studies showing that ROS levels were decreased or not affected by MFs. Multiple factors could cause these discrepancies, including but not limited to MF type/intensity/frequency, exposure time and assay time-point, as well as different biological samples examined. It will be necessary to investigate the influences of different MFs on ROS in various biological samples systematically and mechanistically, which will be helpful for people to get a more complete understanding about MF-induced biological effects. In addition, reviewing the roles of MFs in ROS modulation may open up new scenarios of MF application, which could be further and more widely adopted into clinical applications, particularly in diseases that ROS have documented pathophysiological roles.

The Role of Antioxidant Enzymes in the Ovaries

Proper physiological function of the ovaries is very important for the entire female reproductive system and overall health. Reactive oxygen species (ROS) are generated as by-products during ovarian physiological metabolism, and antioxidants are indicated as factors that can maintain the balance between ROS production and clearance. A disturbance in this balance can induce pathological consequences in oocyte maturation, ovulation, fertilization, implantation, and embryo development, which can ultimately influence pregnancy outcomes. However, our understanding of the molecular and cellular mechanisms underlying these physiological and pathological processes is lacking. This article presents up-to-date findings regarding the effects of antioxidants on the ovaries. An abundance of evidence has confirmed the various significant roles of these antioxidants in the ovaries. Some animal models are discussed in this review to demonstrate the harmful consequences that result from mutation or depletion of antioxidant genes or genes related to antioxidant synthesis. Disruption of antioxidant systems may lead to pathological consequences in women. Antioxidant supplementation is indicated as a possible strategy for treating reproductive disease and infertility by controlling oxidative stress (OS). To confirm this, further investigations are required and more antioxidant therapy in humans has to been performed.

The Combination of Physical Exercise with Muscle-Directed Antioxidants to Counteract Sarcopenia: A Biomedical Rationale for Pleiotropic Treatment with Creatine and Coenzyme Q10

Sarcopenia represents an increasing public health risk due to the rapid aging of the world's population. It is characterized by both low muscle mass and function and is associated with mobility disorders, increased risk of falls and fractures, loss of independence, disabilities, and increased risk of death. Despite the urgency of the problem, the development of treatments for sarcopenia has lagged. Increased reactive oxygen species (ROS) production and decreased antioxidant (AO) defences seem to be important factors contributing to muscle impairment. Studies have been conducted to verify whether physical exercise and/or AOs could prevent and/or delay sarcopenia through a normalization of the etiologically relevant ROS imbalance. Despite the strong rationale, the results obtained were contradictory, particularly with regard to the effects of the tested AOs. A possible explanation might be that not all the agents included in the general heading of "AOs" could fulfill the requisites to counteract the complex series of events causing/accelerating sarcopenia: the combination of the muscle-directed antioxidants creatine and coenzyme Q10 with physical exercise as a biomedical rationale for pleiotropic prevention and/or treatment of sarcopenia is discussed.

Dietary supplementation of organic selenium improves growth, survival, antioxidant and immune status of meagre, Argyrosomus regius, juveniles

Oxidative stress is considered one of the main obstacles to immune competence and high mortality rate of marine fish larvae due to the high dietary polyunsaturated fatty acids and accelerated metabolic rate. This study was carried out to assess the effect of different dietary selenium (Se) yeast on growth, antioxidant status, hematological changes, and cellular and humoral immune parameters in meagre (Argyrosomus regius). Juvenile specimens (3.20 ± 0.17 g) were randomly assigned to four experimental groups, a control group fed a basal diet and another three groups fed Se-supplemented diets at doses of 1, 2 and 3 mg Se-yeast kg^-1 diet for 63 days and the final analyzed selenium concentrations were 0.77, 1.51, 2.97 and 3.98 mg Se kg^-1 diet, respectively. The results indicated that growth performance, feed conversion ratio and survival were significantly improved with 2.97 and 3.98 mg Se-yeast kg^-1 compared to the control group. The catalase, superoxide dismutase activities and total antioxidant status were significantly increased, and thiobarbituric reactive substances in liver homogenate were significantly decreased with increasing Se supplementation respect to the control fish in a dose-dependent manner. Furthermore, hematological and innate immune parameters (immunoglobulin, lysozyme, myeloperoxidase, ACH₅₀ and respiratory burst activity) were also significantly higher in fish fed the Se-yeast supplemented diets compared to the control group. The results demonstrated that the supplementation of 3.98 mg Se-yeast kg^-1 diet improves growth performance, antioxidant balance and innate immune status of meagre juveniles.

Interactions of GST Polymorphisms in Air Pollution Exposure and Respiratory Diseases and Allergies

PURPOSE OF REVIEW

The purpose of this review is to summarize the evidence from recently published original studies investigating how glutathione S-transferase (GST) gene polymorphisms modify the impact of air pollution on asthma, allergic diseases, and lung function.

RECENT FINDINGS

Current studies in epidemiological and controlled human experiments found evidence to suggest that GSTs modify the impact of air pollution exposure on respiratory diseases and allergies. Of the nine articles included in this review, all except one identified at least one significant interaction with at least one of glutathione S-transferase pi 1 (GSTP1), glutathione S-transferase mu 1 (GSTM1), or glutathione S-transferase theta 1 (GSTT1) genes and air pollution exposure. The findings of these studies, however, are markedly different. This difference can be partially explained by regional variation in the exposure levels and oxidative potential of different pollutants and by other interactions involving a number of unaccounted environment exposures and multiple genes. Although there is evidence of an interaction between GST genes and air pollution exposure for the risk of respiratory disease and allergies, results are not concordant. Further investigations are needed to explore the reasons behind the discordancy.

Redox Control of Skeletal Muscle Regeneration

Skeletal muscle shows high plasticity in response to external demand. Moreover, adult skeletal muscle is capable of complete regeneration after injury, due to the properties of muscle stem cells (MuSCs), the satellite cells, which follow a tightly regulated myogenic program to generate both new myofibers and new MuSCs for further needs. Although reactive oxygen species (ROS) and reactive nitrogen species (RNS) have long been associated with skeletal muscle physiology, their implication in the cell and molecular processes at work during muscle regeneration is more recent. This review focuses on redox regulation during skeletal muscle regeneration. An overview of the basics of ROS/RNS and antioxidant chemistry and biology occurring in skeletal muscle is first provided. Then, the comprehensive knowledge on redox regulation of MuSCs and their surrounding cell partners (macrophages, endothelial cells) during skeletal muscle regeneration is presented in normal muscle and in specific physiological (exercise-induced muscle damage, aging) and pathological (muscular dystrophies) contexts. Recent advances in the comprehension of these processes has led to the development of therapeutic assays using antioxidant supplementation, which result in inconsistent efficiency, underlying the need for new tools that are aimed at precisely deciphering and targeting ROS networks. This review should provide an overall insight of the redox regulation of skeletal muscle regeneration while highlighting the limits of the use of nonspecific antioxidants to improve muscle function. Antioxid. Redox Signal. 27, 276-310.

Serum antioxidant capacity, biochemical profile and body composition of breast cancer survivors in a randomized Mediterranean dietary intervention study

PURPOSE

Increasing evidence suggests that Mediterranean Diet (MD) is correlated with reduced risk of breast cancer (BC) and cancer mortality, since it modifies patients' serum antioxidant capacity, body composition and biochemical parameters. The aim of the study was to investigate whether a dietary intervention based on MD has a beneficial effect on these factors.

METHODS

In this intervention study, seventy female BC survivors were randomly assigned to (1) the intervention group (personalized dietary intervention based on MD) and (2) the control group (received the updated American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and ad libitum diet). Both groups were assessed twice [beginning, end of study (after 6 months)] regarding their anthropometric and biochemical parameters, serum vitamin C, vitamin A, a-tocopherol and CoQ10 levels, dietary intake and adherence to MD. An additional intermediate analysis was conducted on participants' body composition and biochemical profile.

RESULTS

Concerning the intervention group, body weight, body fat mass, waist circumference, body mass index as well as HDL-cholesterol were significantly decreased (P < 0.2%). An increase was observed in the vitamin C levels in blood (P < 0.2%). In the control group, body weight, body fat mass and serum total cholesterol rose (P < 0.2%). At the end of the study the two groups were significantly different considering blood glucose, vitamin C, polyunsaturated fatty acids, vitamin A and a-tocopherol levels.

CONCLUSIONS

This randomized dietary intervention based on MD managed to ameliorate serum antioxidant capacity, body composition, adherence to MD and glycemic profile of postmenopausal BC survivors.

Combination of coenzyme Q10-loaded liposomes with ultrasound targeted microbubbles destruction (UTMD) for early theranostics of diabetic nephropathy

Diabetic nephropathy (DN) is one of the most common and lethal microvascular complications of diabetes. This study aimed to explore whether coenzymeQ10 (CoQ10) as an antioxidant combined with ultrasound-targeted microbubble destruction (UTMD) could reverse the progress of early diabetic nephropathy (DN). CoQ10 has great potential to treat early DN. However, the clinical application of CoQ10 has been limited because of its low aqueous solubility and non-specific distribution. Therefore, CoQ10-loaded liposomes (CoQ10-lip) were prepared and combined with ultrasound microbubbles for the early theranostics of DN. CoQ10-lip exhibited a good round morphology with a diameter of 183±1.7nm and a negative zeta potential of -25.3mV, which was capable of prolonging the release of the encapsulated CoQ10. The early DN rat models were induced by streptozotocin (STZ) and confirmed by contrast-enhanced ultrasound (CEUS) and 24-h urinary albumin. After the administration of CoQ10-lip combined with the UTMD technique to rats with early DN, the morphology and function of the kidney were evaluated by ultrasonography, histological and molecular analyses. The renal hemodynamics were significantly improved, moreover, 24-h urinary protein, and oxidative stress indexes were modulated after treatment with CoQ10-lip+UTMD indicating recovery of renal function. An elevated level of Nphs2 protein and reduced caspase 3 level indicated the preservation of podocytes and inhibition of cell apoptosis after CoQ10-lip+UTMD treatment. The molecular mechanism was associated with the upregulation of Bcl-2 and the downregulation of Bax. Moreover, the combination of CoQ10-lip and ultrasound microbubbles demonstrated a better protective effect on the damaged kidney than the other groups (free CoQ10 or CoQ10-lip+/- UTMD). Conclusively, CoQ10-lip in combination with ultrasound microbubbles might be a potential strategy to reverse the progress of early DN.

Physiological importance of polyamines

Polyamines are polycationic molecules that contain two or more amino groups (-NH3 +) and are present in all eukaryotic and prokaryotic cells. Polyamines are synthesized from arginine, ornithine, and proline, and from methionine as the methyl-group donor. In the traditional pathway for polyamine synthesis, arginase converts arginine into ornithine, which is decarboxylated by ornithine decarboxylase (ODC1) to generate putrescine. The latter is converted to spermidine and spermine. Recent studies have indicated the existence of 'non-classical pathways' for the generation of putrescine from arginine and proline in animal cells. Specifically, arginine decarboxylase (ADC) catalyzes the conversion of arginine into agmatine, which is hydrolyzed by agmatinase (AGMAT) to form putrescine. Additionally, proline is oxidized by proline oxidase to yield pyrroline-5-carboxylate, which undergoes transamination with glutamate to produce ornithine for decarboxylation by ODC1. Intracellular production of polyamines is controlled by antizymes binding to and inactivating ODC1. Polyamines exert effects that include stimulation of cell division and proliferation, gene expression for the survival of cells, DNA and protein synthesis, regulation of apoptosis, oxidative stress, angiogenesis, and cell-cell communication activity. Accordingly, polyamines are essential for early embryonic development and successful pregnancy outcome in mammals. In this paper the main concepts on the history, structure and molecular pathways of polyamines as well as their physiological role on angiogenesis, and reproductive physiology are reviewed.

NKX6.3 Regulates Reactive Oxygen Species Production by Suppressing NF-kB and DNMT1 Activities in Gastric Epithelial Cells

NKX6.3 plays an important role in gastric epithelial differentiation and also acts as a gastric tumor suppressor. The specific aim of this study was to determine whether NKX6.3 contributes to gastric mucosal barrier function by regulating reactive oxygen species (ROS) production. NKX6.3 reduced ROS production and regulated expression of anti-oxidant genes, including Hace1. In addition, NKX6.3 reduced DNMT1 expression and activity by down-regulating NF-kB family gene transcription. Silencing of Hace1 recovered ROS production, whereas knock-down of DNMT1 and NF-kB reduced ROS production and induced Hace1 expression by hypomethylating its promoter region. In addition, NKX6.3 inhibited CagA effects on cell growth, ROS production, and NF-kB and DNMT1 activity. In gastric mucosae and cancers, NKX6.3 and Hace1 expression was significantly reduced. The NKX6.3 expression was positively correlated with Hace1 and Nrf2 genes, but negatively correlated with DNMT1. Hypermethylation of Hace1 gene was observed only in gastric mucosae with H. pylori, atrophy and intestinal metaplasia. Thus, these results suggest that NKX6.3 inhibits ROS production by inducing the expression of Hace1 via down-regulating NF-kB and DNMT1 activity in gastric epithelial cells.

Gas-Phase Oxidation via Ion/Ion Reactions: Pathways and Applications

Here, we provide an overview of pathways available upon the gas-phase oxidation of peptides and DNA via ion/ion reactions and explore potential applications of these chemistries. The oxidation of thioethers (i.e., methionine residues and S-alkyl cysteine residues), disulfide bonds, S-nitrosylated cysteine residues, and DNA to the [M+H+O]+ derivative via ion/ion reactions with periodate and peroxymono-sulfate anions is demonstrated. The oxidation of neutral basic sites to various oxidized structures, including the [M+H+O]+, [M-H]+, and [M-H-NH3]+ species, via ion/ion reactions is illustrated and the oxidation characteristics of two different oxidizing reagents, periodate and persulfate anions, are compared. Lastly, the highly efficient generation of molecular radical cations via ion/ion reactions with sulfate radical anion is summarized. Activation of the newly generated molecular radical peptide cations results in losses of various neutral side chains, several of which generate dehydroalanine residues that can be used to localize the amino acid from which the dehydroalanine was generated. The chemistries presented herein result in a diverse range of structures that can be used for a variety of applications, including the identification and localization of S-alkyl cysteine residues, the oxidative cleavage of disulfide bonds, and the generation of molecular radical cations from even-electron doubly protonated peptides. Graphical Abstract ᅟ.

Quercetin ameliorates imiquimod-induced psoriasis-like skin inflammation in mice via the NF-κB pathway

Quercetin (QC) is a dietary flavonoid abundant in many natural plants. A series of studies have shown that it has been shown to exhibit several biological properties, including anti-inflammatory, anti-oxidant, cardio-protective, vasodilatory, liver-protective and anti-cancer activities. However, so far the possible therapeutic effect of QC on psoriasis has not been reported. The present study was undertaken to evaluate the potential beneficial effect of QC in psoriasis using a generated imiquimod (IMQ)-induced psoriasis-like mouse model, and to further elucidate its underlying mechanisms of action. Effects of QC on PASI scores, back temperature, histopathological changes, oxidative/anti-oxidative indexes, pro-inflammatory cytokines and NF-κB pathway in IMQ-induced mice were investigated. Our results showed that QC could significantly reduce the PASI scores, decrease the temperature of the psoriasis-like lesions, and ameliorate the deteriorating histopathology in IMQ-induced mice. Moreover, QC effectively attenuated levels of TNF-α, IL-6 and IL-17 in serum, increased activities of GSH, CAT and SOD, and decreased the accumulation of MDA in skin tissue induced by IMQ in mice. The mechanism may be associated with the down-regulation of NF-κB, IKKα, NIK and RelB expression and up-regulation of TRAF3, which were critically involved in the non-canonical NF-κB pathway. In conclusion, our present study demonstrated that QC had appreciable anti-psoriasis effects in IMQ-induced mice, and the underlying mechanism may involve the improvement of antioxidant and anti-inflammatory status and inhibition on the activation of the NF-κB signaling. Hence, QC, a naturally occurring flavone with potent anti-psoriatic effects, has the potential for further development as a candidate for psoriasis treatment.

Differential expression of AP-1 transcription factors in human prostate LNCaP and PC-3 cells: role of Fra-1 in transition to CRPC status

Androgen receptor (AR) signaling axis plays a vital role in the development of prostate and critical in the progression of prostate cancer. Androgen withdrawal initially regresses tumors but eventually develops into aggressive castration-resistant prostate cancer (CRPC). Activator Protein-1 (AP-1) transcription factors are most likely to be associated with malignant transformation in prostate cancer. Hence, to determine the implication of AR and AP-1 in promoting the transition of prostate cancer to the androgen-independent state, we used AR-positive LNCaP and AR-negative PC-3 cells as an in vitro model system. The effect of dihydrotestosterone or anti-androgen bicalutamide on the cell proliferation and viability was assessed by MTT assay. Expression studies on AR, marker genes-PSA, TMPRSS2, and different AP-1 factors were analyzed by semi-quantitative RT-PCR and expressions of AR and Fra-1 proteins were analyzed by Western blotting. Dihydrotestosterone induced the cell proliferation in LNCaP with no effect on PC-3 cells. Bicalutamide decreased the viability of both LNCaP and PC-3 cells. Dihydrotestosterone induced the expression of AR, PSA, c-Jun, and Fra-1 in LNCaP cells, and it was c-Jun and c-Fos in case of PC-3 cells, while bicalutamide decreased their expression. In addition, constitutive activation and non-regulation of Fra-1 by bicalutamide in PC-3 cells suggested that Fra-1, probably a key component, involved in transition of aggressive androgen-independent PC-3 cells with poor prognosis.

Hypoxia-Induced Oxidative Stress Modulation with Physical Activity

Increased oxidative stress, defined as an imbalance between prooxidants and antioxidants, resulting in molecular damage and disruption of redox signaling, is associated with numerous pathophysiological processes and known to exacerbate chronic diseases. Prolonged systemic hypoxia, induced either by exposure to terrestrial altitude or a reduction in ambient O2 availability is known to elicit oxidative stress and thereby alter redox balance in healthy humans. The redox balance modulation is also highly dependent on the level of physical activity. For example, both high-intensity exercise and inactivity, representing the two ends of the physical activity spectrum, are known to promote oxidative stress. Numerous to-date studies indicate that hypoxia and exercise can exert additive influence upon redox balance alterations. However, recent evidence suggests that moderate physical activity can attenuate altitude/hypoxia-induced oxidative stress during long-term hypoxic exposure. The purpose of this review is to summarize recent findings on hypoxia-related oxidative stress modulation by different activity levels during prolonged hypoxic exposures and examine the potential mechanisms underlying the observed redox balance changes. The paper also explores the applicability of moderate activity as a strategy for attenuating hypoxia-related oxidative stress. Moreover, the potential of such moderate intensity activities used to counteract inactivity-related oxidative stress, often encountered in pathological, elderly and obese populations is also discussed. Finally, future research directions for investigating interactive effects of altitude/hypoxia and exercise on oxidative stress are proposed.

Pathophysiology of peripheral arterial disease in diabetes mellitus

Peripheral arterial disease (PAD) increases the risk of lower extremity amputation. It is also an independent predictor of cardiovascular and cerebrovascular ischemic events, affecting both the quality and expectancy of life. Many studies have demonstrated that the prevalence of PAD in patients with diabetes mellitus (DM) is higher than in non-diabetic patients. In diabetic patients, PAD occurs early with rapid progression, and is frequently asymptomatic. Multiple metabolic aberrations in DM, such as advanced glycation end-products, low-density lipoprotein cholesterol, and abnormal oxidative stress, have been shown to worsen PAD. However, the role of DM in PAD is not completely understood. The purpose of the present article is to review and discuss the pathophysiology of PAD in DM.

MECHANISMS IN ENDOCRINOLOGY: Nutrition as a mediator of oxidative stress in metabolic and reproductive disorders in women

Nutrition can generate oxidative stress and trigger a cascade of molecular events that can disrupt oxidative and hormonal balance. Nutrient ingestion promotes a major inflammatory and oxidative response at the cellular level in the postprandial state, altering the metabolic state of tissues. A domino of unfavorable metabolic changes is orchestrated in the main metabolic organs, including adipose tissue, skeletal muscle, liver and pancreas, where subclinical inflammation, endothelial dysfunction, mitochondrial deregulation and impaired insulin response and secretion take place. Simultaneously, in reproductive tissues, nutrition-induced oxidative stress can potentially violate delicate oxidative balance that is mandatory to secure normal reproductive function. Taken all the above into account, nutrition and its accompanying postprandial oxidative stress, in the unique context of female hormonal background, can potentially compromise normal metabolic and reproductive functions in women and may act as an active mediator of various metabolic and reproductive disorders.

Topical Application of TAT-Superoxide Dismutase in Acupoints LI 20 on Allergic Rhinitis

Reactive oxygen species are products of cellular metabolism and assigned important roles in biomedical science as deleterious factors in pathologies. In fact, some studies have shown that the therapeutic benefits of taking antioxidants were limited and the potential for therapeutic intervention remains unclear. New evidences showed that ROS have some ability of intercellular transportation. For treating allergic rhinitis, as a novel intracellular superoxide quencher, TAT-SOD applied to acupoints LI 20 instead of directly to nasal cavity can be used to test that. TTA group apply TAT-SOD cream prepared by adding purified TAT-SOD to the vehicle cream to acupoints LI 20, while placebo group used the vehicle cream instead. TTN group applied the same TAT-SOD cream directly to nasal cavity three times daily. Symptom scores were recorded at baseline and days 8 and 15. For the overall efficacy rate, TTA group was 81.0%, while placebo group was 5.9% and TTN was 0%. Malondialdehyde levels decreased observably in TTA group, and superoxide dismutase, catalase, and glutathione peroxidase levels remained basically unaffected. Enzymatic scavenging of the intracellular superoxide at acupoints LI 20 proved to be effective in treating allergic rhinitis, while no improvement was observed with the placebo group and TTN group.

Response of human pulps to different in-office bleaching techniques: preliminary findings

This study evaluated a whitening effect and the likely side effect (tooth sensitivity and pulp response) of human teeth subjected to different in-office bleaching (IOB) techniques and materials, mainly the presence of calcium in the IOB materials. A calcium-free (CF) and a calcium-containing (CC) 35% hydrogen peroxide (HP) gels were evaluated. The CF was refreshed every 15 minutes, three times (CF 3-15) or in a single 45-min application (CF 1-45) at one bleaching appointment. The CC was used only in a single 45-min application (CC 1-45). Each technique was applied in 5 mandibular incisors scheduled for extraction for different patients. In control group, no tooth bleaching was performed. The tooth colour (TC) and tooth sensitivity (TS) were recorded at baseline and after IOB. The teeth were extracted 2 days after the application of IOB and subjected to histological analysis. The data was submitted to appropriate statistical analysis (α=0.05). The changes of TC were similar between groups and statistically different from the control (p<0.05). However, TS of groups bleached with CF was statistically higher than that recorded for CC and the control (p<0.05). In CF 3-15 and CF 1-45 groups, the coronal pulp tissue exhibited partial necrosis associated with tertiary dentin deposition. In CC 1-45 group smaller area of necrosis occurred only in three bleached teeth in which tertiary dentin deposition was observed. The calcium-containing 35%HP gel could be preferable for in-office bleaching because it caused less tooth sensibility and pulp damage.

Gum odina: an emerging gut modulating approach in colorectal cancer prevention

This study is focused on Gum Odina (GO), a reported prebiotic in our earlier work, and its impact on colorectal cancer (CRC).